Can low speed operation of an inverter-driven fan cause the motor to burn out?
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As the title suggests: The motor cooling fan and the spindle drive rotate at the same speed. When the frequency is reduced to a very low level, could this cause the motor temperature to rise excessively, leading to damage? Can the use of variable frequency have an adverse effect on the motor bearings and fan bearings, such as causing misalignment?
Yes, generally, variable-frequency motors are equipped with a separate cooling fan motor.
Frequency conversion affects the motor; it has an impact on the motor bearings only if there are issues with the installation, but it does not affect the fan bearings. The concentricity is adjusted during the installation of both the motor and the fan
If you are using variable-frequency motors, it’s fine to use a lower frequency – the motor won’t get damaged in such cases. However, if it’s a regular motor that has been modified to work with variable frequency, it’s recommended to keep the frequency above 35Hz to prevent the motor from overheating~~
Your motors are lubricated with grease, right? The speed level should not have any impact on the lubrication effect; in fact, it might even be beneficial. As for concentricity, once it’s properly assembled at the beginning, there should be basically no problems~~
This is because ordinary motors rely on their own rotational speed to drive the motor fan for cooling; when the speed is too low, the heat generated by the motor cannot be dissipated. The insulation of the windings deteriorates due to overheating, which can lead to short circuits and ultimately engine damage.
Yes, it’s easy for such motors to get damaged. With a regular motor combined with an inverter, the fan speed decreases when the rotation speed is low, which results in poor heat dissipation. In contrast, variable-frequency motors come equipped with their own fan; even when the rotation speed is low, the fan still operates at its rated speed, thus ensuring proper heat dissipation. Different usage scenarios require different approaches – experienced users may choose to opt for a regular motor along with an inverter in order to save costs, as this still allows for speed control and energy savings.